tests/git-sync: reorganize darwin and linux

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

tests/modules/services/git-sync-darwin/default.nix

@@ -1,5 +0,0 @@
-{ lib, pkgs, ... }:
-
-lib.optionalAttrs pkgs.stdenv.hostPlatform.isDarwin {
-  git-sync = ./basic.nix;
-}

tests/modules/services/git-sync/darwin/default.nix

@@ -0,0 +1,3 @@
+{
+  git-sync = ./basic.nix;
+}

tests/modules/services/git-sync/default.nix

@@ -1,6 +1,3 @@
 { lib, pkgs, ... }:
-
-lib.optionalAttrs pkgs.stdenv.hostPlatform.isLinux {
-  git-sync = ./basic.nix;
-  git-sync-with-whitespace = ./whitespace.nix;
-}
+(lib.optionalAttrs pkgs.stdenv.hostPlatform.isDarwin (import ./darwin/default.nix))
+// (lib.optionalAttrs pkgs.stdenv.hostPlatform.isLinux (import ./linux/default.nix))

tests/modules/services/git-sync/linux/default.nix

@@ -0,0 +1,4 @@
+{
+  git-sync = ./basic.nix;
+  git-sync-with-whitespace = ./whitespace.nix;
+}